The present invention is directed to packaging containers and a device for making the containers. More particularly, the present invention pertains to configurations for a packing container having self-formed end closures, created from a single piece of material. The present invention also pertains to a device for forming the containers.
Packaging for lengthy items takes many forms. One construction includes a pair of corrugated, laminated paperboard top and bottom U-shaped channels configured for one to fit within the other. Most packages formed in this manner require separate end closures or caps, usually manufactured from cardboard or wood. These caps generally are stapled to adjacent package walls. Not only does this method necessitate close-fit manufacturing, but it is also very cumbersome at installation, and may cause content damage due to incompletely formed or off-positioned staples.
In another variety of packaging container, one of the top and bottom U-shaped channels has a notch cut into opposing side walls of the “U,” so that the “U” portion may be folded over at a 90 degree angle. In such a configuration, channel ends are closed by the folded base portion and the side walls of the “U,” which are folded over adjacent side walls. To seal such a package, tape or a like strip-type adhesive sealant must be extended over the flaps that then are folded over the adjacent side walls. Even though a seal may be formed, openings may remain at the juncture of the folded-over base portion and the cover portion, seriously weakening the package. This design is disclosed in U.S. Pat. No. 4,976,374.
Another existing packaging container, disclosed in Loeschen, U.S. Pat. No. 6,382,447, resolves the above-referenced problems by providing a packaging container in which the entirety of the end closure is formed from the packaging material itself. However, the container base unit, which forms end closures for the packaging container, features mitered corners. These mitered corners require complex die-cutting with mirrored tools, and mandatory strapping at specific positions to restrain the miter flaps. The patent to Loeschen, which is commonly assigned herewith, is incorporated herein by reference.
A new, single-piece packaging container cut without miters is disclosed in application Ser. No. 10/264,506, filed Oct. 4, 2002, assigned to the assignee of the present invention and incorporated herein by reference. The end closures of this packaging container are formed from the packaging material itself. The container allows for no gaps at its closure locations, because its end closures meet or overlap along the container's main body portion, providing a high degree of structural strength and package integrity. Manufacturing the container is extremely simple and cost-effective, requiring only two straight saw-cuts on each package end.
Occasionally, packaging containers must accommodate objects with varied local height elevations, or objects that require segregation during shipping or storage. Normally, shippers rely on foam fillers or container partitions to protect such irregularly shaped or fragile objects. Foam fillers may compress, leak, or shift, and container partitions may shift or break during shipping, rendering shippers' attempts to protect their products worthless. Accordingly, there exists a need for specialized configurations for a single-piece packaging container having self-formed end closures, providing better protection for fragile and/or irregularly shaped objects than undependable foam fillers or container partitions.